Issues have been seen where adding 3 or more dry contacts to a NetBotz 200 appliance directly or per pod can cause one of the sensors to replicate. It has been seen where 4 dry contacts may be listed while only 3 are connected. Other strange occurrences have been seen such as phantom alerts for contact closure when none exist. This appears on NetBotz Firmware v3.5.6 (Rack Monitor 200) as well as earlier versions

It is suggested that no more than 2 dry contact sensors be connected to the main unit or per pod. If you have a single appliance and not pod, the limit would be 2 sensors. If you have a single sensor pod connected, you can connect 2 dry contact sensors to the main unit and 2 dry contacts to the sensor pod and so on.

This does not effect temperature /humidity sensors and you can have other sensors connected at the same time as the 2 dry contact cables.